Intershaft compartment buffering arrangement

Patent metadata

Field	Value
Publication number	US-10513938-B2
Application number	US-201715496399-A
Country	US
Kind code	B2
Filing date	Apr 25, 2017
Priority date	Apr 25, 2017
Publication date	Dec 24, 2019
Grant date	Dec 24, 2019

Abstract

Aspects of the disclosure are directed to a system associated with an engine having a central longitudinal axis, including a first shaft axially extending along the central longitudinal axis, a second shaft coaxial with the first shaft, a first air seal that seals between the first shaft and the second shaft at a first axial location, a second air seal that seals between the first shaft and the second shaft at a second axial location, a first oil seal that provides intershaft sealing between the first shaft and the second shaft at a third axial location, a second oil seal that provides intershaft sealing between the first shaft and the second shaft at a fourth axial location axially adjacent to the third axial location, and a high pressure compressor that provides pressurized air to a first radially exterior side of the first air seal and to a second radially exterior side the second air seal.

First claim

What is claimed is:

1. A system associated with an engine having a central longitudinal axis, comprising:
a first shaft axially extending along the central longitudinal axis;
a second shaft coaxial with the first shaft;
a first air seal that seals between the first shaft and the second shaft at a first axial location;
a second air seal that seals between the first shaft and the second shaft at a second axial location;
a first oil seal that provides intershaft sealing between the first shaft and the second shaft at a third axial location;
a second oil seal that provides intershaft sealing between the first shaft and the second shaft at a fourth axial location axially adjacent to the third axial location; and
a high pressure compressor that provides pressurized air to a first radially exterior side of the first air seal and to a second radially exterior side of the second air seal.

2. The system of claim 1 , wherein the first air seal and the second air seal consume a portion of the air.

3. The system of claim 1 , further comprising:
a first oil seal that is substantially located at the first axial location; and
a second oil seal that is substantially located at the second axial location.

4. A gas turbine engine comprising:
an inner shaft;
an outer shaft concentrically surrounding at least a portion of the inner shaft, wherein an interface between the outer shaft and the inner shaft is located within an annulus;
an oil seal positioned within the annulus and configured to prevent lubricating oil in the annulus from entering the interface;
a first air seal that seals between the inner shaft and the outer shaft at a first axial location;
a second air seal that seals between the inner shaft and the outer shaft at a second axial location; and
a high pressure compressor that provides pressurized air to (i) a radially exterior side of the oil seal, (ii) a radially interior side of the oil seal, (iii) a first radially exterior side of the first air seal and (iv) a second radially exterior side of the second air seal.

5. The gas turbine engine of claim 4 , where the outer shaft comprises a high pressure compressor shaft and the inner shaft comprises a low pressure turbine shaft.

6. A gas turbine engine, comprising:
an intershaft seal separating a bearing compartment from an annulus and configured to prevent a lubricating oil in the bearing compartment from entering the annulus;
an outer shaft concentrically surrounding at least a portion of an inner shaft, where an interface between the outer shaft and the inner shaft is located within the annulus;
an oil seal positioned within the annulus and configured to prevent lubricating oil in the annulus from entering the interface;
a first air seal that seals between the inner shaft and the outer shaft at a first axial location;
a second air seal that seals between the inner shaft and the outer shaft at a second axial location; and
a high pressure compressor that provides pressurized air to (i) a radially exterior side of the oil seal, (ii) a radially interior side of the oil seal, (iii) a first radially exterior side of the first air seal and (iv) a second radially exterior side of the second air seal.

7. A system for a gas turbine engine, comprising:
a first shaft axially extending along an engine central longitudinal axis;
a second shaft coaxial with and radially exterior to the first shaft;
a first air seal and oil seal pair at an axial upstream position that seals a bearing compartment with respect to one of the first shaft and the second shaft and a second air seal and oil seal pair at an axial downstream position that seals the bearing compartment with respect to another of the first shaft and the second shaft;
a plurality of intershaft seals radially between the first shaft and the second shaft and axially between the first air seal and oil seal pair and the second first air seal and oil seal pair;
a first air seal that seals between the first shaft and the second shaft at a first axial location;
a second air seal that seals between the first shaft and the second shaft at a second axial location; and
wherein each of the intershaft seals is an oil seal and wherein buffer air diverted from an engine high pressure compressor is delivered to (i) a first intershaft space axially between at least a first pair of adjacent intershaft seals from the plurality of intershaft seals, (ii) a first radially exterior side of the first air seal and (iii) a second radially exterior side of the second air seal.

Assignees

• United Technologies Corp

Inventors

• Witlicki Russell B
• Davis Todd A
• Parnin Francis

Classifications

• F05D2220/32

  in gas turbines · CPC title

• F05D2240/60

  Shafts · CPC title

• F04D27/009

  by bleeding, by passing or recycling fluid · CPC title

• F01D25/183

  Sealing means · CPC title

• F01D25/162

  Bearing supports · CPC title